A straightforward argument exploiting Audenaert's result
leads to a proof of the subadditivity of \(q\) -entropies (Tsallis entropies)
for finite-dimensional bipartite quantum states; see [1]}, [2]} and references therein.
In 2014, Ando [3]}
(or see [4]} for an alternative proof)
established the following remarkable inequality
in the sense of the Löwner ordering.
